The overall objectives of the total project concern the elucidation of parallel pathways in determining psychophysical and evoked potential responses to contrast modulated grating patterns. Another objective concerns the relationship of psychophysical and evoked potential responses in patients with cerebral lesions. In the current year we completed experiments concerning the effect of pattern adaptation on contrast modulation, established the importance of electrode location and spatial and temporal variables on evoked potential responses to contrast modulation, and studied psychophysical and evoked potential responses to grating stimuli in patients with cerebral lesions and amblyopia. In a six-year-old child who had been blind since the age of 2 years, occipital potentials of normal amplitude and waveform could be evoked not only by diffuse light flashes but also by alternating checkerboard and sinusoidal grating patterns of low spatial frequency. Computerized tomography demonstrated destruction of the occipital lobes except to the primary visual projection area. Thus, in man, destruction of visual association cortices may result in loss of vision with partial preservation of pattern-evoked occipital potentials.